Actually, there is only a 1% chance of having a baby with Down Syndrome. However, this statistic is only in general terms. This means that this includes both the people who are at greater risk of having a baby with Down Syndrome and those people who are not at a great risk.
The risks include having babies later in life. If the mother is older like in her 40s when she has a baby, she stands a greater risk of having a baby with Down Syndrome compared to women who are giving birth in the 20s and early 30s. The older mothers have a greater chance. Also, if you the mother already has a baby that has Down Syndrome, there is a greater likelihood that she may have another baby with Down Syndrome.